1. Field of the Invention
The present invention relates to an apparatus and a method for coating a substrate such as a semiconductor wafer, an LCD substrate, or the like with a resist and developing it.
2. Description of the Related Art
In the photo-resist process among semiconductor device fabrication processes, a resist solution is coated on the surface of a semiconductor wafer (hereinafter referred to as xe2x80x9ca waferxe2x80x9d) to form a resist film thereon. After a predetermined pattern is exposed on the resist film, a developing solution is applied to the substrate to be fabricated and the substrate is developed. Conventionally such resist-coating processing and developing processing are performed by a processing system in which a plurality of processing units are integrated and a substrate is transferred between the units by a transfer device. The transfer of substrates to/from the processing system is performed by a mounting section housing a plurality of substrates.
The processing units in the aforesaid processing system are spinner-type resist coating unit and developing unit, a heating unit, a cooling unit, and the like. A wafer housed in the mounting section is carried into and out of these processing units by the transfer device and again housed in the mounting section.
In the processing system configured as above, in some cases, a wafer is not normally processed, that is, a wafer is abnormally processed in the above processing units. For instance, the supply of a solution is accidentally stopped in the resist coating unit or the developing unit, the wafer is not mounted at a normal position, or notice of abnormal processing is given from an aligner side. In such cases, in order not to waste an expensive wafer, it is required to inspect whether the abnormally processed wafer can be advanced to the subsequent step and handled similarly to a normally processed wafer, and to continue the processing when the wafer can be handled similarly.
In the above inspection, for example, abnormally processed wafers are selected out of a plurality of wafers which have undergone processing and are housed in a mounting section, and the selected wafers are transferred to an inspection device.
Wafers which are judged by the inspection device as to be handled similarly to normally processed wafers are returned again to the mounting section. The other wafers undergo surface peeling and are reprocessed from the beginning, or are abandoned.
However, there are disadvantages that the selection of abnormally processed wafers out of a plurality of wafers which have undergone processing and are housed in the mounting section takes time and labor, and that when the wafers are not exactly selected, the subsequent processing for the wafers is wasted. Especially in a processing system having a plurality of mounting sections, abnormally processed wafers are dispersed in respective mounting sections, in which case it is not easy to exactly select the abnormally processed wafers.
An object of the present invention is to provide a substrate processing apparatus and a substrate processing method in which abnormally processed wafers can be exactly taken out and subjected to inspection and the like.
Another object of the present invention is to provide a substrate processing apparatus and a substrate processing method in which substrates processed previous to ordinary processing can be exactly taken out and subjected to inspection and the like.
To attain these objects, the present invention is a substrate processing apparatus including a first mounting section housing a plurality of substrates before and after processing, a process section processing the substrate, a second mounting section housing a plurality of the substrates abnormally processed in the process section or a plurality of the substrates processed previous to ordinary processing therein, and means for transferring the substrate between the first mounting section, the process section, and the second mounting section.
In the present invention, the second mounting section housing a plurality of substrates abnormally processed in the process section and a plurality of substrates processed previous to ordinary processing therein is provided in addition to the first mounting section housing a plurality of substrates before and after processing, and abnormally processed substrates or previously processed substrates are collected in the second mounting section. Thus, the abnormally processed substrates can be exactly taken out and subjected to inspection and the like, and the substrates processed previous to ordinary processing can be exactly taken out and subjected to inspection and the like.
These objects and still other objects and advantages of the present invention will become apparent upon reading the following specification when taken in conjunction with the accompanying drawings.